Various forms of heat shields are known and used as thermal protection for a wheel and pneumatic tire mounted thereon against the influx of heat generated by a high performance disc brake completely or partially housed in the wheel. Reference is made to U.S. Pat. No. 3,051,528 to Raymond R. Rogers (common assignee) and U.S. Pat. Application Ser. No. 424,142 filed Dec. 12, 1973 in the name of C. P. Han (common assignee) now abandoned for examples of pertinent heat shields.
Heat shields of the above-mentioned prior art type are not entirely satisfactory for one or more reasons including limited ability to retard heat flow, exposure to dirt and/or brake debris which tends to adhere to the shield causing disassembly problems as well as reduced efficiency, maintenance requirements which may be time consuming and expensive, and limited clearance with the inner surface of the wheel and/or outer periphery of the stack of brake discs thereby restricting air flow volume over the same as well as making installation and/or removal of the wheel from the brake difficult.
Also depending upon the material from which the friction discs are made as, for example, carbon, it has been found that the frictional characteristics of the material are adversely affected by water, brake fluid or similar liquids that may drip or otherwise be thrown into the brake.